Over the last three decades, interest in Infrared (IR) technology as a medium to convey information has grown considerably. This is reflected by the increasing number of devices such as laptops, PDAs, and mobile phones that incorporate optical wireless transceivers and also by the increasing number of optical wireless links available for indoor and outdoor use. The popularity of IR is based on the advantages it has over radio including unregulated bandwidth, immunity to radio interference, and inherent security."Optical Wireless Communications" examines some of the most important features of optical wireless communication systems. It considers the benefits and limitations of IR as a medium conveying information wirelessly and compares the advantages and disadvantages of infrared to microwave and other radio systems. It also details the evolution of IR communication systems and describes atmospheric and other types of data transmission limitations. The book presents design fundamentals of optical concentrators, as well as a review of some of the most important receiver optical front-ends (containing imaging or non-imaging concentrators and optical filters), including an explanation of the different sources of infrared noise and an introduction to eye safety. It also describes optical wireless transmitter and receiver design issues, typical modulation, coding, and multiple access techniques, and introduces IrDA protocols and wireless IR networking.